1. Field of the Invention
The invention relates to an antenna and more particularly to a wideband antenna.
2. Description of Related Art
With the development of mobile communication devices with multi-functions and characterized by miniaturization, a newly developed antenna (i.e., antenna under test, AUT) must pass verification tests and product certification tests in a short-range test environment, so as to ensure that the radiation pattern of the antenna meets the application requirements of the mobile communication devices. The AUT is placed in a small shield room in the short-range test environment, and a calibration antenna in the shield room is used in the verification test or product certification test for the AUT.
In general, because the horn antenna is characterized by its wide bandwidth, most of the existing shield rooms employ the horn antenna as the calibration antenna of the AUT in the verification test and the product certification test. However, the horn antenna is often so large and thus may not be applied in the small shield rooms. Therefore, how to design a wideband antenna within a limited space as a calibration antenna applied in the small shield rooms is one of the major issues occurring in the verification test and the product certification.